Lasting Effects of Pain :: Biology Essays Research Papers

Lasting Effects of PainINTRODUCTIONOnce upon a typical sunny day, Mary, Susie, and Jackie argon jumping rope. Unbeknownst to them, as they chirrup their rhymes, Mikey and Kenny hide in the bushes planning a surprise attack. Just as Marys little feet b atomic number 18ly lift off the ground, the two boys leap towards the girls and dig them into the dirt. Ouch they all scream as everyone hits the dirt. Mary is up on her feet with her knees skin and bleeding. A smile slowly crept on her face as she try to hold back a chuckle. Whats so funny? asked Mikey, as everyone false to look at her. Arent you supposed to get mad and chase us around? Mary shrugs and looks down at her knees. Doesnt that hurt? asks Jackie. So what scarce does Mary feel when she hurts her knees? Pain, of course. But, how exactly does she experience it? Well, inside Marys tissues lie nociceptors. Nociceptors are specialized sensory nerves that are activated when there is a potential for danger, such as Mary fallin g to the ground. The stimulation of nociceptors, first, allows large-diameter, myelinated axons to carry rapidly conducted action potentials. This causes the sensation of a sharp, well-localized, pricking or cutting irritation. It is then followed by a diffuse burning or aching pain caused by more slowly propagated action potentials that are carried by smaller, less heavily myelinated axons (1). The action potentials are generated and conveyed to the important nervous system by way of a difference in electrical potential (2). When the threshold potential difference for each nocicpetor is mooted, a signal is sent to the central nervous system. As the signal continues to turn on to the spinal cord, the medulla, the thalamus, and then the cerebral cortex, it must pass by means of a series of gates (3). According to the gate theory of pain, the awareness of pain can only get to the brain by passing through a series of gates (Melzack and Hall, 1965). To open a gate, a congregation of small neurons that form a pain pool must reach their threshold. When it is reached, the signal is allowed to be sent higher. So as Mary and everyone else who fall to the ground, their body is undergoing this awareness of pain. Kenny is next to stand up. Owww, theres sand in my leg, he whimpered unhappily. Hey, you pushed us, and now youre crying?